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A salt marsh or saltmarsh, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open salt water or brackish water that is regularly flooded by the tides. It is dominated by dense stands of salt-tolerant plants such as herbs, grasses, or low shrubs.〔Adam, P (1990). Saltmarsh Ecology. Cambridge University Press. New York.〕〔Woodroffe, CD (2002). Coasts: form, process and evolution. Cambridge University Press. New York.〕 These plants are terrestrial in origin and are essential to the stability of the salt marsh in trapping and binding sediments. Salt marshes play a large role in the aquatic food web and the delivery of nutrients to coastal waters. They also support terrestrial animals and provide coastal protection.〔 ==Basic information == Salt marshes occur on low-energy shorelines in temperate and high-latitudes〔Allen, JRL, Pye, K (1992). Saltmarshes: morphodynamics, conservation, and engineering significance. Cambridge University Press. Cambridge, UK.〕 which can be stable or emerging, or submerging if the sedimentation rate exceeds the subsidence rate. Commonly these shorelines consist of mud or sand flats (known also as tidal flats or abbreviated to mudflats) which are nourished with sediment from inflowing rivers and streams.〔Chapman, V. J. (1974). Salt marshes and salt deserts of the world. Phyllis Claire Chapman, Germany.〕 These typically include sheltered environments such as embankments, estuaries and the leeward side of barrier islands and spits. In the tropics and sub-tropics they are replaced by mangroves; an area that differs from a salt marsh in that instead of herbaceous plants, they are dominated by salt-tolerant trees.〔Adam, P (1990). Saltmarsh Ecology. Cambridge University Press. New York.〕 Most salt marshes have a low topography with low elevations but a vast wide area, making them hugely popular for human populations.〔Bromberg-Gedan, K., Silliman, B. R., and Bertness, M. D. (2009). Centuries of human driven change in salt marsh ecosystems, ''Annual Review of Marine Science'', 1: 117-141.〕 Salt marshes are located among different landforms based on their physical and geomorphological settings. Such marsh landforms include deltaic marshes, estuarine, back-barrier, open coast, embayments and drowned-valley marshes. Deltaic marshes are associated with large rivers where many occur in Southern Europe such as the Camargue, France in the Rhone delta or the Ebro delta in Spain. They are also extensive within the rivers of the Mississippi Delta in the United States.〔Woodroffe, CD (2002). Coasts: form, process and evolution. Cambridge University Press. New York.〕 In New Zealand, most salt marshes occur at the head of estuaries in areas where there is little wave action and high sedimentation.〔Te Ara - The Encyclopedia of New Zealand (2005-2010). Plants of the Estuary. Retrieved 15 March 2010, from http://www.teara.govt.nz/en/estuaries/3〕 Such marshes are located in Awhitu Regional Park in Auckland, the Manawatu Estuary, and the Avon-Heathcote Estuary in Christchurch. Back-barrier marshes are sensitive to the reshaping of barriers in the landward side of which they have been formed.〔 They are common along much of the eastern coast of the United States and the Frisian Islands. Large, shallow coastal embayments can hold salt marshes with examples including Morecambe Bay and Portsmouth in Britain and the Bay of Fundy in North America.〔 Salt marshes are sometimes included in lagoons, and the difference is not very marked; the Venetian Lagoon in Italy, for example, is made up of these sorts of animals and or living organisms belonging to this ecosystem. They have a big impact on the biodiversity of the area. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「salt marsh」の詳細全文を読む スポンサード リンク
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